32 ANACARDIACEAE. 



AXACARDIACEAE Lindl. Sumac Family. 



Small trees or shrubs, with milky acrid juice, alternate odd-pinnate 

 exstipulate leaves, and perfect or polygamous greenish or yellowish flow- 

 ers. Sepals, petals, and stamens 5. Styles or stigmas 3. Fruit a small 

 dry drupe. Represented by the genus Rhus L. 



* Flowers polygamous, in terminal thyrsoid panicles. 



R. typhina L. Staghorn Sumac. Tree 1 0-20 feet high; wood yellow, young- 

 branches densely villous; leaflets 11-31, sessile, lanceolate, acuminate, serrate, 

 pale pubescent beneath; fruit red, with long- crimson hairs. Wooded hill- 

 sides; May-June: frequent; Winneshiek, Allamakee. Clayton, Dubuque, 

 Fayette, Jackson. Delaware, Scott, Jones, and Emmet counties. (R. hirta f L.) 

 Sudw.) 



R. glabra L. Common S. Shrub 3-15 feet high; branches smooth, some- 

 what glaucous; leaflets 11-31, sessile, lanceolate-oblong, acuminate, serrate, 

 pale beneath; fruit red, with short crimson hairs. Open uplands, thickets: 

 June: common. 



** Flowers polygamous , in loose axillary panicles. 



i^. radicans L. Poison Oak. Poison Ivy. Bushy, 1-2 feet high or else a 

 woody vine, climbing high: leaflets 3, ovate, acuminate, entire, sinuate or 

 somewhat lobed, more or less pubescent beneath; fruit globular, smooth, 

 white or yellowish. Rich soil, waysides and thickets: June; common. 

 Usually given as R. toxicodendron L. 



* * * Flowers polygamo-dboecious, appearing before the leaves, in terminal spicate 

 clusters. 



R. canadensis Marsh. Shrub 2-6 feet high; leaflets 3, crenately toothed, 

 pubescent when young, later glabrate, lateral ones ovate, sessile, terminal 

 one ovate with a cuneate base, short stalked; fruit globose, red, pubescent. 

 Rocky woods; April; frequent; Delaware, Muscatine. Lee, Hentw, Wapello. 

 Van Buren, Jefferson, and Linn counties. (R. aromatica Ait.) 



POLYG-ALACEAE Richenb. Milkwort Family. 



Ours herbs, with simple entire alternate, opposite or verticillate ex- 

 stipulate leaves, and mostly racemose, spicate, or axillary flowers. Pedi- 

 cels frequently 2-bracted at the base. Flowers perfect, irregular. 

 Sepals 5, the upper and 2 lower small and often greenish, the 2 lateral 

 large, colored. Petals 3, united into a split tube, more or less adnate to 

 the stamens. Stamens 6 or 8, monodelphous or diadelphous: anthers 1- 

 celled, opeuiug at the apex by a hole or chink. Ovary 2-celled, 2-ovuled; 

 style simple. Fruit a 2-celled 2-seeded capsule. Seeds usually caruncled 

 and hairy. Represented in our flora by the genus Polygala L. 



P. senega L. Seneca Sndkeroot. Perennial; glabrous or nearly so; root- 

 stocks hard, knotty; stems several; 6-12 inches high; leaves lanceolate or ob- 

 long-lanceolate, alternate, sessile, lower small, scale-like; flowers white, in a 

 solitary close spike; wings round-obovate. Rocky woods: May-June: fre- 

 quent; Winneshiek, Fayette, Scott, Muscatine, Johnson, Story, and Cerro 

 ( tordo counties. 



P. songuinea L. Annual; stem mostly simple. 6-15 inches high, glabrous: 

 Leaves oblong linear, alternate, sessile; flowers in a globular or oblong head, 

 rose-purple, greenish, rarely white; wings broadly ovate, sessile, exceeding 

 tin- pod. Moist prairies: June-September; common. (P. vlridescens L.) 



P. incarnata L. Annual, glaucous; stem simple, slender; leaves distant, 



